By TIM FAULKNER/ecoRI News staff

BURRILLVILLE, R.I. — A leaky diaper is a prime suspect in an outbreak of a bacterial infection at two Burrillville lakes.

According to the state Department of Health (DOH), the bacteria Shigella sonnei is the cause for 134 illnesses and 16 hospitalizations after swimmers at Spring Lake Beach were infected July 4 and 5. An additional 14 cases of Shigellosis were reported July 10-12 in people who swam at Wallum Lake, which borders Rhode Island and Massachusetts.

At a July 9 press conference in Providence, DOH director Michael Fine said the outbreak was rare and likely due to fecal matter left in the water by a swimmer or a splashing toddler. He urged all parents to be sure infants and toddlers wear diapers and a swimsuit when they go in the water.

It's not believed that the bacteria traveled to the lake from stormwater runoff or a flooded cesspool, state officials said, as the bacteria can't survive without a host. Anyone suffering from diarrhea should wait 48 hours after recovering before swimming, the DOH advises.

Massachusetts health officials said only one Massachusetts resident contracted Shigellosis. The illness wasn't associated with a Massachusetts lake or other body of water.

Those sick range in age from 11 months to 31 years. None of the illnesses are life-threatening. Most occurred July 4, when some 2,000 visitors were at Spring Lake Beach.

Shigella doesn't last long outside the body, so the risk of further infections is likely gone, Fine said. The 750-foot-long beach reopened July 10.

The last Shigella infection in Rhode Island occurred at the beach at Lincoln Woods in the late 1980s. “There’s no reason it’s likely to happen again,” Fine said.